1. Field of the Invention
The present invention relates to a miniature air compressor, and more particularly to a miniature air compressor that may provide a stable pressurized air flow whose noise and impurity may be eliminated by the noise suppression cylinder, thereby enhancing the usage effect of the injection pen device.
2. Description of the Related Art
A conventional air compressor may be used in an injection pen driven by a pneumatic tool, so that the injection pen may evenly inject various paint for coloring patterns.
The closest prior art of which the applicant is aware is disclosed in the Taiwanese Patent Publication No. 369089, entitled by xe2x80x9cAir Compressorxe2x80x9d. The air compressor includes a valve plug secured in a valve chamber, a spring having a first end mounted on the valve plug and a second end provided with an air valve which may be rested on the valve port for controlling the direction of the air flow. However, the air compressor has a complicated construction. In addition, the spring is pushed and moved reciprocally, so that the spring easily produces fatigue, and so that the air valve cannot seal and close the valve port completely.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional air compressor.
The primary objective of the present invention is to provide a miniature air compressor that may provide a stable pressurized air flow whose noise and impurity may be eliminated by the noise suppression cylinder, thereby enhancing the usage effect of the injection pen device.
Another objective of the present invention is to provide a miniature air compressor that has a simple construction.
A further objective of the present invention is to provide a miniature air compressor that may be assembled and amended easily and conveniently, and may reduce the cost of production.
In accordance with the present invention, there is provided a miniature air compressor, comprising a motor, a compression cylinder, a lower valve seat, an upper valve seat, and a noise suppression cylinder, wherein:
the motor has a central shaft for driving an eccentric cam which may drive a piston crank to move upward and downward reciprocally, so that a piston mounted in the compression cylinder may be axially moved upward and downward reciprocally;
the compression cylinder is secured on the motor;
the lower valve seat is mounted on the compression cylinder, and has a first side formed with an air inlet recess and a second side formed with an air outlet recess, the air inlet recess of the lower valve seat has a top face formed with an arcuate cavity, an air inlet valve plate is movably mounted in the arcuate cavity of the air inlet recess of the lower valve seat, the air outlet recess of the lower valve seat has a top face formed with an annular protruding push post for pushing an air outlet valve plate upward;
the upper valve seat is mounted on a top face of the lower valve seat, and has a first side formed with an air inlet and a second side formed with an air outlet, the air inlet of the upper valve seat has a bottom formed with a protruding push post for pushing the air inlet valve plate downward, the air outlet of the upper valve seat has a bottom formed with an arcuate cavity, and the air outlet valve plate is movably mounted in the arcuate cavity of the air outlet of the upper valve seat; and
the noise suppression cylinder is secured on the motor, an air inlet pipe has a fist end mounted on a top end of the noise suppression cylinder, and a second end mounted on a top face of the air inlet of the upper valve seat.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.